The Merlin 1D engine was judged flight-ready after firing for a total of nearly 33 minutes over the course of 28 different tests at SpaceX's rocket-development facility in McGregor, Texas. The new engine will soon be incorporated into the company's Falcon 9 rocket, officials said.

"The Merlin 1D successfully performed every test throughout this extremely rigorous qualification program," SpaceX CEO and chief designer Elon Musk said in a statement. "With flight qualification now complete, we look forward to flying the first Merlin 1D engines on Falcon 9’s Flight 6 this year."

The Falcon 9 has flown five times to date, most recently on March 1, when it blasted the robotic Dragon capsule toward the International Space Station on California-based SpaceX's second contracted supply run for NASA. According to the company's launch manifest, flight number six will launch a Canadian communications satellite, likely in mid-June. [SpaceX's Amazing Rockets & Spaceships (Photos)]

Company officials say the Merlin 1D will provide a big boost for the Falcon 9, which until now has been powered by Merlin 1C engines in its first stage (nine of them, hence the name).